Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence, which is the emission of light without heat.
In the case of a glowing flower, the scientists use a chemical called fluorophore to create the fluorescence. Fluorophores are molecules that absorb light and then emit light of a longer wavelength.
The scientists use a gene gun to insert the gene that codes for the fluorophore into the flower's DNA. The flower then produces the fluorophore, which absorbs light from the sun and emits light of a longer wavelength, making the flower glow.
This technology could be used to create a variety of glowing plants, which could be used for decorative purposes or to create light in areas where there is no electricity.
